Col de l'Arpalle

Overview

Col de l'Arpalle is a long, patient climb: 23.9 km of continuous elevation gain that carries you from 710 m at the base to 2030 m at the summit. That is a net gain of 1320 m, with 1290 m of total ascent — numbers close enough to tell you this is a climb that rarely lets you coast. The average gradient sits at 5.53%, which sounds civil on paper but hides a maximum ramp of 15.64%. This is a category-1 ascent, one rung below hors catégorie, and it earns that rating through sheer duration as much as steepness. Settle in; you will be turning the pedals for a long time.

How the Gradient Unfolds

The defining feature of Arpalle is length. Over 23.9 km, a 5.53% average produces a climb whose character is one of relentless accumulation rather than a single brutal wall. But the 15.64% maximum is the warning: this is not a metronomic slope. Expect the road to drift between easier stretches — where the gradient dips well below the average and lets you recover — and sharp pitches that spike toward that 15.64% figure. Because the summit crests at 2030 m, thinner air compounds the effort in the final kilometres. The last third of a 1320 m ascent, done at altitude, is where the climb quietly extracts its toll. Ride the steep ramps conservatively; there is always more climb ahead of you than behind.

Pacing Notes

On a climb this long, pacing is everything. Anchor your effort to your sustainable threshold rather than the gradient in front of you: a climb of 23.9 km should be ridden just below or around your FTP, not chased in surges over every ramp. If you do not know your threshold, run the numbers through the FTP estimator before you start, then hold that ceiling. The temptation on the 15.64% pitches is to stand and force the pace — resist it. Absorb the steep sections at a slightly higher effort, then recover on the shallower gradients rather than pushing harder there. With 1320 m to gain and altitude thickening toward 2030 m, the rider who paces the first 15 km sensibly is the one still moving well at the top.

Gearing

For a 23.9 km climb averaging 5.53% and spiking to 15.64%, gear for the ramps, not the average. A compact 34-tooth chainring is the sensible front. For the cassette, a 34×32 is the practical minimum most fit riders will want — it keeps your cadence alive on the steeper pitches without grinding. If you climb at a lower power-to-weight, or simply want insurance for the 15.64% sections after 1300-plus metres of ascent, step up to a 34×34. The extra sprocket costs nothing on the easy stretches and buys you a spinning gear exactly when the road stands up and the altitude bites.

Summary

Col de l'Arpalle rewards patience: a long, steady category-1 climb with enough steep punctuation to punish anyone who starts too hard. Pace to threshold, gear generously, and respect the altitude in the final kilometres.

Length: 23.9 km
Average gradient: 5.53%
Max gradient: 15.64%
Start: 710 m
Summit: 2030 m
Net gain: 1320 m
Total ascent: 1290 m
Category: 1